Puppet has about 200 settings, all of which are listed in the configuration reference. Most of the time, you interact with only a couple dozen of them. This page lists the most important ones, assuming that you're okay with default values for things like the port Puppet uses for network traffic. See the configuration reference for more details on each.

There are a lot of settings that are rarely useful but still make sense, but there are also at least a hundred that shouldn’t be configurable at all. This is a Puppet design choice. Because of the way Puppet code is arranged, the settings system is the easiest way to publish global constants that are dynamically initialized on startup. This means a lot of things have been introduced to Puppet as configurable settings regardless of whether they needed to be configurable.

Settings for agents (all nodes)

The following settings for agents are listed approximately in order of importance. Most of these can go in either [main] or [agent] sections, or be specified on the command line.

Basics

server — The master server to request configurations from. Defaults to puppet. Change it if that’s not your server’s name.

ca_server and report_server — If you’re using multiple masters, you’ll need to centralize the CA. One of the ways to do this is by configuring ca_server on all agents. See the multiple masters guide for more details. The report_server setting works the same way, although whether you need to use it depends on how you’re processing reports.

certname — The node’s certificate name, and the unique identifier it uses when requesting catalogs. Defaults to the fully qualified domain name.

For best compatibility, you should limit the value of certname to only use letters, numbers, periods, underscores, and dashes. That is, it should match /\A[a-z0-9._-]+\Z/.

The special value ca is reserved, and can’t be used as the certname for a normal node.

environment — The environment to request when contacting the master. It’s only a request, though; the master’s ENC can override this if it chooses. Defaults to production.

sourceaddress — The address on a multihomed host to use for the agent’s communication with the master server.

Note: Although it’s possible to set something other than the certname as the node name (using either the node_name_fact or node_name_value setting), we don’t generally recommend it. It allows you to re-use one node certificate for many nodes, but it reduces security, makes it harder to reliably identify nodes, and can interfere with other features. Setting a non-certname node name is not officially supported in Puppet Enterprise.

Run behavior

These settings affect the way Puppet applies catalogs:

noop — If enabled, the agent won’t make any changes to the node. Instead, it looks for changes that would be made if the catalog were applied, and report to the master about what it would have done. This can be overridden per-resource with the noopmetaparameter.

priority — Allows you to make the agent share CPU resources so that other applications have access to processing power while agent is applying a catalog.

report — Indicates whether to send reports. Defaults to true, and under most circumstances should be left there.

tags — Lets you limit the Puppet run to include only those resources with certain tags.

trace, profile, graph, and show_diff — Tools for debugging or learning more about an agent run. Useful when combined with the --test and --debug command options.

usecacheonfailure — Indicates whether to fall back to the last known good catalog if the master fails to return a good catalog. The default behavior is usually what you want, but you might have a reason to disable it.

ignoreschedules — If you use schedules, this can be useful when doing an initial Puppet run to set up new nodes.

prerun_command and postrun_command — Commands to run on either side of a Puppet run.

Service behavior

These settings affect the way Puppet agent acts when running as a long-lived service:

runinterval — How often to do a Puppet run, when running as a service.

waitforcert — Whether to keep trying if the agent can’t initially get a certificate. The default behavior is good, but you might have a reason to disable it.

Useful when running agent from cron

splay and splaylimit — Together, these allow you to spread out agent runs. When running the agent as a daemon, the services usually have been started far enough out of sync to make this a non-issue, but it’s useful with cron agents. For example, if your agent cron job happens on the hour, you could set splay = true and splaylimit = 60m to keep the master from getting briefly overworked and then left idle for the next 50 minutes.

daemonize — Whether to daemonize. Set this to false when running the agent from cron.

onetime — Whether to exit after finishing the current Puppet run. Set this to true when running the agent from cron.

Settings for master servers

Many of these settings are also important for standalone Puppet apply nodes, since they act as their own master. These settings should usually go in [master]. However, if you’re using Puppet apply in production, put them in [main] instead.

Basics

dns_alt_names — A list of hostnames the server is allowed to use when acting as a master. The hostname your agents use in their server setting must be included in either this setting or the master’s certname setting. Note that this setting is only used when initially generating the master’s certificate — if you need to change the DNS names, you must:

catalog_terminus — This can enable the optional static compiler. If you have lots of file resources in your manifests, the static compiler lets you sacrifice some extra CPU work on your master to gain faster configuration and reduced HTTPS traffic on your agents. See the indirection reference for details.

CA settings

ca_ttl — How long newly signed certificates should be valid for. Deprecated.

autosign — Whether and how to autosign certificates. See Autosigning for detailed information.